A double multi-vane type rotary fluid machine system is described in Japanese Patent Application Laid-open No. 59-41602. In this rotary fluid machine system, a circular vane-supporting ring is disposed between an elliptic outer cam ring and an elliptic inner cam ring, and outer and inner ends of a plurality of vanes radially slidably supported on the vane-supporting ring are in abutment against an inner peripheral surface of the outer cam ring and an outer peripheral surface of the inner cam ring, respectively. Therefore, when the vane-supporting ring is rotated relative to the outer cam ring and the inner cam ring, the volumes of a plurality of vane chambers partitioned by the vanes between the outer cam ring and the vane-supporting ring are increased or decreased and in this manner, the rotary fluid machine system functions as an expander or compressor. In addition, the volumes of a plurality of vane chambers partitioned by the vanes between the inner cam ring and the vane-supporting ring are increased or decreased and in this manner, the rotary fluid machine system functions as an expander or compressor.
In this double multi-vane type rotary fluid machine system, the outer and inner rotary fluid machines can be used as independent expanders, respectively; the outer and inner rotary fluid machines can be used as independent compressors, respectively; and one and the other of the outer and inner rotary fluid machines can be used as an expander and a compressor, respectively.
A vane-type rotary fluid machine system capable of being used as an expander or a compressor is described in Japanese Patent Application Laid-open No. 60-206990. In this rotary fluid machine system, a circular intermediate cylinder is disposed eccentrically between a circular outer cam ring and a circular inner cam ring disposed concentrically with each other, and outer and inner ends of a plurality of vanes radially slidably supported in the intermediate cylinder are in abutment against an inner peripheral surface of the outer cam ring and an outer peripheral surface of the inner cam ring, respectively. Therefore, when the intermediate cylinder is rotated relative to the outer cam ring and the inner cam ring, the volumes of a plurality of vane chambers partitioned by the vanes between the outer cam ring and the intermediate cylinder are increased or decreased and in this manner, the rotary fluid machine system functions as an expander or a compressor. In addition, the volumes of a plurality of vane chambers partitioned by the vanes between the inner cam ring and the intermediate cylinder are increased or decreased and in this manner, the rotary fluid machine system functions as an expander or a compressor.
In this vane-type rotary fluid machine system, the outer and inner rotary fluid machines can be used as independent expanders, respectively; the outer and inner rotary fluid machines can be used as independent compressors, respectively; and in addition, the outer and inner rotary fluid machines can be connected in line to each other and operated as a two-stage expander or a two-stage compressor by allowing a working fluid passed through one of the outer and inner rotary fluid machines to be passed through the other rotary fluid machine.
It should be noted here that in the conventional vane-type rotary fluid machine system, a rotor supporting cylinders and the vanes is formed by a single member and hence, it is difficult to enhance the working accuracy for vane grooves, and there is a possibility that clearances between the vane grooves and the vanes may be uneven, resulting in a reduction in wear resistance and a reduction in sealability. The conventional vane-type rotary fluid machine system also suffers from a problem that a central portion of the rotor accommodating the cylinders therein is heated to a high temperature, but since the rotor is formed by a single member, it is easy for a heat of the central portion to be transmitted to an outer peripheral portion having the vanes accommodated therein, and the above-described disadvantage is further increased due to the thermal deformation, and moreover, the heat of the central portion of the rotor is easy to escape to the outside, resulting in a reduction in heat efficiency. In addition, since the rotor is formed by the single member, even when there is a disadvantage in a portion of the rotor, the entire rotor is required to be replaced by a new rotor, which is inconvenient for the cost.